FIG. 1 is a structure diagram of a traditional cellular wireless communication system; as shown in FIG. 1, the cellular wireless communication system is mainly composed of a core network (CN), a radio access network (RAN) and terminals. Wherein, the CN is responsible for the non-access stratum service, for example: terminal location updating, etc., and the CN is the anchor point of the user plane. The RAN includes: a base station, or a base station and base station control; the RAN is responsible for the access stratum service, for example: wireless resources management, etc.; there can exist physical or logical connections among the base stations according to the actual conditions, such as the connection between the base station 1 and the base station 2 and the connection between the base station 1 and the base station 3 as shown in FIG. 1; and each base station can be connected with more than one CN nodes. The terminal, that is, the user equipment (UE), refers to various devices which can communicate with the cellular wireless communication network, for example: a mobile telephone or a notebook computer, etc.
The MTC service refers to: the service for communicating by machines between machines. In the MTC service, with no need of people's participation, all communications are finished by the machine autonomously, which obtains the data through the perception device such as a sensor, etc., and then reports the data to the mobile communication network through a communication module, and accesses to the public data network through the mobile communication network. The MTC service can include: logistics monitoring, safety monitoring, telemedicine detection, and the applications such as remote meter reading etc. The data of the MTC service are managed by a particular server of the mobile operator or a specialized MTC operator, which are available for checking by the MTC user or the MTC administrator. In this process, the device obtaining the data required by the service is a terminal.
The MTC service has introduced the characteristics different from the traditional mobile communication, such as the MTC characteristic based on the group. When the MTC characteristic based on the group is activated, the network can control, manage or charge the MTC terminal grouping according to the demand of the operator. Like that, the MTC characteristic based on the group provides a simple and easy mode in which the group is regarded as a granularity to control/update/charge the MTC terminal, and reduces the surplus signaling to avoid causing the network congestion. When the quantity of the MTC terminal is very large, it can also save the network resources by using the MTC characteristic based on the group. Every terminal within a group can be in the same area, and/or have the same MTC characteristics attribute, and/or belong to the same MTC user; for the network, every terminal in the group is visible.
As to the MTC characteristic based on the group, when the MTC user subscribes a terminal group, the operator need to set and activate the group characteristic in the subscription information of every terminal in the group, and stores the subscription information of every terminal after setting in a home subscriber information unit. The home subscriber information unit includes a Home Subscriber Server (HSS) or a Home Location Register (HLR), which is an entity responsible for storing the identity information, the authentication information and the authorization information of the terminal device, etc., in the core network. According to different situations, the HSS or the HLR can be used for storing the user identity information and the binding information of the user and the terminal device, or only for storing the user identity information (the binding information of the user and the terminal device can be stored by the gateway), or for storing the identity information of the terminal device directly. The HSS or the HLR is further responsible for the subscription database of the user, and executing the identity authentication and authorization of the user, etc. the service platform can inquire the user or terminal information from the HSS or the HLR.
As shown in FIG. 2, it is a framework diagram of a MTC communication system. When the terminal is attached to the network, the mobility management unit obtains the subscription information of that terminal from the HSS or the HLR, and stores the information locally. The mobility management unit includes a mobility management entity (MME) or a serving GPRS supporting node (SGSN) or a Mobile Switching Center (MSC), which is a unit that is responsible for managing the terminal access control, location information updating and switching in the core network, and is responsible for the function of controlling the non-access stratum signaling from the core network to the terminal and registering the terminal to the network.
The machine type communication interworking function (MTC IWF) is a connection entity between a mobile communication network and an external public network, which can realize functions such as protocol conversion, address inquiry, information storage, etc. The interworking function entity is connected to an MTC application server externally, and may be connected to the HSS/HLR or the MME/SGSN/MSC internally.
Usually in some processes, for example, the server needs to trigger the terminal to establish the connection with the server through the MTC IWF, or the MTC IWF needs to obtain the terminal accessibility of the terminal, then the MTC IWF needs to obtain the service node information of the terminal from the HSS or the HLR, or obtain the terminal accessibility information of the terminal from the HSS or the HLR. The service node information is the address of the service MME or SGSN or MSC of the terminal. Now aiming at the MTC characteristic based on the group, such as, dividing the MTC terminals into groups to perform controlling/updating/charging, there is already a solution which selects a terminal group representative MME and a terminal group representative S-GW according to the group information, and controls the terminal group accessibility process and the periodic location updating of the terminal group, etc., according to the group information.
However, after introducing the MTC characteristic based on the group, the function of the existing network is unable to manage the terminal group through the MTC IWF according to the group information, thus avoiding the network congestion caused by that the server or the MTC IWF needs to obtain service node information or terminal accessibility information of a large number of MTC terminals of the terminal group from the HSS or the HLR at the same time.